10 DEFINT A-Z: DEFDBL P,T
20 KEY OFF: SCREEN 1: COLOR 0, 1: CLS : PI = 3.141592654#
30 LINE (160, 0)-(160, 199), 3,,&H3333: LINE (0, 30)-(319, 30), 3,,&H3333
40 X0 = 160: Y0 = 30: FOR I = 1 TO 360
50 T = I * PI / 180
60 X = INT(40 * (2 * SIN(T) - SIN(2 * T)) + 0.5) + 160
70 Y = INT(- 40 * (2 * COS(T) - COS(2 * T)) + 0.5) + 70
80 LINE (X0, Y0)-(X, Y), 2
90 X0 = X: Y0 = Y
100 NEXT I
110 WHILE INPUT$(1) = "": WEND
120 SCREEN 0: WIDTH 80: CLS : END

